Big Sister
by ALargeBear
Summary: An afternoon tutoring Chika leads to a realization for Dia.


Dia was, in all important aspects, the model older sister. Prim and proper, but never shying away from doting and pampering. It was something she took great pride in, and never once was it unfulfilling or a chore, but there were always certain thoughts. Small and insignificant, but they were persistent, and wouldn't stop their incessant nagging.

What they were, Dia wasn't all that sure. Always rearing their head after a long day spent consoling or coddling Ruby. A yearning for something that she had never experienced herself, but exactly what it was, she never could put into words.

It was a feeling always reserved for after comforting and doting on Ruby. So when that nagging came back, but this time alone with Chika in the girl's room, it was a surprise. A lazy afternoon with nobody around. Just the two of them. Largely quiet, outside of the groans and complaints from Chika as she worked on some homework or another.

"I'm still not sure why I had to tutor you," Dia said, looking through a halfway completed assignment of Chika's. "I'm sure Riko could have done just as good a job at this."

"She wanted to work on the new song. She said I can be a distraction sometimes." Chika's head was on the table, disinterested eyes looked at the papers and books strewn all across without any rhyme or reason. "So I thought it'd be a good idea not to ask."

Dia set the assignment down, making a quick mark before sliding it back to Chika for correction. "What about You?"

"She's not that good at studying either." Chika sat up and took the paper, correcting the mistakes. "When it's just us, we don't get much work done anyway. We always end up doing anything else."

Dia sighed as Chika filled out another worksheet, probably riddled with errors, just like the last one. "I know Kanan does pretty well with her studies. Why not ask her?"

"Same problem with You." Chika looked up, boredom clear as day on her face, but there was the barest hint of determination to get things done. "We always get distracted, and I wanted to actually focus this time."

"So that's why you asked me?" Dia didn't want to let it out, but the sting was evident in her tone. a smidge quieter than before, shaky in a way it never was.

"I asked because I knew you wouldn't let me goof around." Chika smiled, trying to meet Dia's eyes, but missing each time. "Plus, I like to see you in big sister mode. Normally I only get to see it when you're with Ruby."

"Then you need to get back to work and stop talking." The previous weakness gone as Dia sobered herself, hoping to get back on task. Chika's eyes were so invasive and earnest, it was scary in a way. "These handouts aren't going to do themselves."

"Fine."

Things fell back into their established routine. Chika would try and answer all the questions on a worksheet, and Dia would inevitably tell her that a good chunk was wrong. It was an odd sort of back and forth, Dia wasn't sure she'd ever experienced anything like it. Maybe with Mari, but that was always for strange antics instead of actual effort. Chika was sincere in everything she did, and homework wasn't any different.

It was hard for her to correct and reprimand Chika like she would anyone else. Ruby was meek and never questioned, Kanan could stand on her own, and Mari didn't care. Was it possible for someone to care too much or try to hard? If it was, Dia knew Chika exemplified it in ways nobody else could. With each correction and redo, Dia didn't get that usual burst of satisfaction or pride. All she got was that indescribable urge for something that couldn't be properly pinned down, and looking over to Chika worsened it each time.

Chika asked questions in ways Ruby never would. Maybe that was it.

"I tried that formula you told me before. I think I got it, but I want you to check again to make sure," Chika said as she slid another paper across the table. Her words were collected, not a hint of self-doubt or anything mumbled. Though the boredom was always there,

Dia blinked, taking a second to reorient herself, the question plain and simple in a foreign way. She took the paper, giving it a quick once-over. "It looks right. Now you just need to fill out the rest of the page, then we'll be done with that one."

Chika didn't give an audible answer, smiling and taking the paper back. There was a vigor and determination to how Chika went back to work. Not born in a want to study, but a want to get something done.

"How's this." Chika handed back the finished paper.

Dia looked it over. It had taken many tires, but Chika had gotten to where she needed. The handwriting was sloppy, but the answers right.

"This all looks right," Dia said. "Good work, Chika."

Chika smiled back, not answering as she leaned back with a heavy sigh.

It was strange. Dia didn't get that same satisfaction from giving Chika praise. With Ruby, it was always an immediate burst of gratitude and more often than not a quick hug. A smile. That was it, and Dia couldn't rationalize why it didn't feel right.

Was it because it wasn't enough thanks? No, Dia never did help for the praise, it would be hollow otherwise. Was it because she wanted to hear that praise come from Chika instead? Dia had to look away from Chika's suddenly radiant smile. Something started to click into place in a way she did not want to think about.

"Did you need help with anything else?" Dia asked, her eyes down on the table, trying to find anything to take her attention.

"Nope." Chika sat up straight. "That was the last of it. Thanks so much for helping me. I couldn't have gotten all this done without you. All this work can be so boring sometimes, but I have to get it done."

Dia propped her elbows up on the table, burying her warm face in her hands. "Just don't fall behind like this in the future. It's bad for you, and it wouldn't look good for Aqours if one of our members couldn't compete because of their grades."

There wasn't an ounce of confidence in anything Dia said. Thoughts caught on the way Chika's untampered joy drew her in. Inviting her to spill emotions that were unbecoming of someone so proud of her role as the eldest Kurosawa daughter. They could be pushed back, but their presence was new, and altogether hard for Dia to understand. Just what did she want out of Chika? That uncertainty fueling strange urges to be pampered by someone so radiant.

"So," Chika spoke, head still lolled back and shoulders loose. "What's Ruby doing today?"

"I'm sorry?" Dia tilted her, the question strange.

"Well, you're her bigger sister, right?" Chika asked. Dia slowly nodded. "Don't big sisters know all about what their little sisters are doing. I know my sisters always make sure they know where I am. They can be pretty big worrywarts sometimes, and I bet you are too."

"I'm not a 'worrywart', but yes I know where Ruby is. She's with Kanan and Mari working on the steps for the new song, and when she's done they're going to walk her home." Dia crossed her arms, still struggling to look Chika head on. The question helping to build those hard to describe thoughts. "I fail to see how this helps with your homework."

"It doesn't," Chika said. "But I said it before, right? I like seeing you be big sister Dia, and not student council Dia. It's fun."

"There's a difference?" Dia asked.

"A big difference!" Chika shot up, back ramrod straight and exuberant smile creeping across her lips. "When we're with Aqours you're like, all serious and strict. Which is a good thing because we need it so much. Big sister Dia is strict too and always keeps me on track, but you also praise me and smile real nice."

Dia went red, exposed and open in such a foreign way. Her head quickly went down and voice lowered. "I just tried to help you get your work done in a timely fashion. I thought you'd work better if I praised you sometimes like I do with Ruby, that's all."

"And it worked because you're the best, and I know Ruby thinks the same thing." Chika let things linger a moment before speaking back up. This time quieter, and with an odd Chika-like sense of knowing. "What's it like being the big sister anyway?"

Dia's first words caught in her throat. An immediate reaction and dismissal that she'd practiced for years. I try my best to be a good sister for Ruby and a good daughter to my parents, was what she always said. It was impossible to give such a bland, not fully truthful answer to an inquisitive Chika. Dia wondered if she picked up on her own internal struggle. It wouldn't have been much of a surprise, and that thought made Dia reconsider.

"It can be hard sometimes to have expectations put on you because you were the firstborn." It tumbled out, and Dia's eyes darted up towards Chika's in a panic expecting some judgment, but she was wrong. She was met with simple and inviting eyes. "But I'm glad to have a sister as wonderful as Ruby, and I very much enjoy making sure she's happy and has a good role model to look up to. Even if I do sometimes wonder what it would be like to switch places with her."

"You think that way, too?" Chika asked.

Dia didn't answer, lifting her head and quirking an eyebrow instead.

"I always wondered what it'd be like to have a little sister, you know?" Chika crossed her arms. "I've always been the baby of the family."

"I have Ruby, so I'm not sure you mean," Dia said. Chika rolled her eyes, urging her to continue. "But I guess I have tried to imagine myself in Ruby's place a few times."

It was out in the open. Thoughts that she'd just come to terms with had been spilled out in front a girl she'd known for months. Embarrassing in ways that Mari's antics could never rival. As she tried to get any sort of read from Chika's still soft smile, her heart sped up. A side she'd never shown anyone, a side she'd now come to understand, and Chika was the one to pull it out. Dia couldn't deny it made sense as she couldn't look away from Chika, that smile offering some solace to sweaty palms and a rapid heartbeat.

"Then let me be your big sister for the rest of the day," Chika said.

Dia blinked. Fear and anxieties still there. "I don't understand?"

"Well, you're always being all sweet with Ruby. Helping with her homework, making her happy when she's sad, and being a great big sister, right?"

"I try to do all those things, yes."

"Then let me do some of those things for you instead." Chika slid around from the opposite end of the table, now off to Dia's side.

"I'm not sure what you could help me with." Dia found confidence in Chika's unabashed enthusiasm. "You can't even study on your own without someone's help."

"Then we won't study." Chika pushed her face in closer to Dia's, still a good distance between them. "I can teach you how to swim."

Dia reared back, cheeks still red. "I already know how to do that."

"Oh, duh." Chika put a hand to her chin. "Then how about I protect you from some bullies."

"Nobody bullies me." Dia rolled her eyes. A tension was still on her shoulders, but a smile came easier than before, small, but it was something.

"Of course they don't." Chika hummed. "Than what else do big sisters do?"

"You have two of your own. Why not think about what they do for you?"

"You want me to yell at you for being reckless and annoying the guests?" Chika asked, tilting her head as if the question weren't out of place.

"I don't even know what that means," Dia questioned whether that pull she felt toward Chika was still there. It was, and Chika's off-kilter antics were a good balm for the hard to soothe fears. "What I meant was what kind of things do they do that make you happy, or something you'd only let them do."

"Well, I'm always happiest when Shima peels mikans for me on cold days and feeds them to me," Chika said. "Should we do that?"

Tempting as it was for Dia to relent, succumb to a yearning that wasn't going away, her pride and nerves wouldn't allow it. "Absolutely not."

"Then I'm out of ideas." Chika pulled her head back, plopping it on the table with a sigh. "What do you do with Ruby when she's sad or wants attention?"

"W-Well, there is one thing." Dia scratched just under her lips, trying not to look at Chika. "She likes to lay her head in my lap if she's really upset or scared about something."

"That's a great idea." Chika didn't waste time, sitting up and swinging her knees out from under the table. "We can do that then."

Could she allow herself this bit of pampering? Dia wondered if it was okay. To rely on someone younger, and that someone being Chika. She couldn't escape the need that she'd come to realize was a want to be coddled. That nagging after pampering Ruby now making sense after so long. She wanted that herself. Not as often, and not from anyone, but there was a need to be filled. A need for something she'd always only given.

"I don't think that's a good idea." Dia's dismissal was tepid at best, the cracks showing through in ways she'd never experienced.

"Come on.' Chika patted her thighs that were covered in loose sweatpants. "Just for a little bit. I want to try being someone's big sister, and I bet you've always wondered what it felt like for Ruby."

She was found out, but there was never much of an illusion otherwise. Dia had long decided Chika was much too good at things like this, but her heart still pounded away. Nervous and timid, but not scared. Her sweaty hands clenched tight. It was Chika, so it was okay. Dia repeated that mantra over and over in her head.

"Just once," Dia said, crawling over to Chika's side, their bodies close.

Chika beamed, still patting her lap with vigor.

It was slow. Dia took deep breaths as she laid her head down. Chika's clothing covered lap offering a surprising amount of comfort. The warmth new and indulgent in a way she'd never felt. There was a vulnerability that Dia hadn't experienced before, but that was paired with a strange security that Chika brought.

They were close, and Dia couldn't find anything to say. The pampering was nice and helped lull her into a comfort that she'd before only thought was reserved for Ruby. Her heart still beat quick and her breathing was still off, but it comfortable. A sense of affection that she'd only recently been able to understand as something she wanted.

Chika kept her hands at her side, looking down Dia. "Is this all you do."

"No." Dia closed her eyes. "Sometimes I run my fingers through Ruby's hair. She says that calms her down the most."

Even Kanan and Mari never doted her in such an intimate way. Dia would never allow it, but Chika was an exception. As inexperienced and clumsy fingers ran through her hair, Dia knew she'd found that feeling she was looking for. The quiet of the room helped her get lost in affection she'd never felt. Her heart returned to its normal rhythm, and all her pent-up frustration and fears faded into the background.

"Am I doing it right?" Chika whispered, fingers entwined with locks of black hair.

Dia hummed an affirmative. "You're not going to tell anyone about this, right?"

"Of course not."

Shifting her head into a more comfortable spot, Dia drifted further from all her anxieties and expectations. Chika's hand in her hair offered a comfort that she'd never known, and she hoped it wouldn't be the last time.


End file.
